Additional Articles


External Article

Two-Dimensional Interval Packing Challenge

Packing intervals is a classic SQL task that involves packing groups of intersecting intervals to their respective continuous intervals. In mathematics, an interval is the subset of all values of a given type, e.g., integer numbers, between some low value and some high value.

2024-01-17

External Article

Eager Aggregation in SQL queries

Aggregation is a widely used way to summarize the content of a database. It is usually expressed with GROUP BY clause or just using aggregate functions (like COUNT or SUM). When the database engine executes a query with aggregations, it produces individual rows need to compute the required output and then performs the aggregation as (almost) last step. We discuss in this article how to re-write a query manually so that the order of operations will be different and when it can be beneficial.

2024-01-15

Technical Article

Always On Availability Groups Troubleshooting and Monitoring Guide

This guide helps you get started on troubleshooting some of the common issues in AlwaysOn Availability Groups and monitoring AlwaysOn Availability Groups. It is intended to provide original content as well as a landing page of useful information that is already published elsewhere.

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2024-01-09 (first published: )

Technical Article

Customizing Statistics Histogram in SQL Server 2019

The use of statistics in SQL Server is tightly embedded in the query optimizer and query processor. The creation and maintenance of statistics is usually handled by the SQL Server engine, though many DBAs and developers know that periodically we might need to update those statistics to ensure good performance of queries. SQL Server 2019 gives us more options.

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2024-01-09 (first published: )

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Technical Article

Data Saturday #8 - SouthWest US

This Data Saturday Event is being jointly developed by the Albuquerque Data Platform Users Group, Arizona Data Platform Users Group, and the Santa Fe Data Platform Users Groups. This event will include sessions on many Microsoft Data Platform related topics. Join us on May 15, 2021.

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2024-01-09 (first published: )

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Fun with JSON II

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Fun with JSON II

Changing Data Types

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Changing Data Types

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Question of the Day

Fun with JSON II

I have some data in a table:

CREATE TABLE #test_data
(
    id INT PRIMARY KEY,
    name VARCHAR(100),
    birth_date DATE
);

-- Step 2: Insert rows  
INSERT INTO #test_data
VALUES
(1, 'Olivia', '2025-01-05'),
(2, 'Emma', '2025-03-02'),
(3, 'Liam', '2025-11-15'),
(4, 'Noah', '2025-12-22');
If I run this query, how many rows are returned?
SELECT t1.[key] AS row,
       t2.*
FROM OPENJSON(
     (
         SELECT t.* FROM #test_data AS t FOR JSON PATH
     )
             ) t1
    CROSS APPLY OPENJSON(t1.value) t2;

See possible answers